Concrete wall form panel unit with facing-reinforcing and insulating means



Aug. 18, 1964 G. F. BowDl-:N 3,144,701

CONCRETE wALx. FORM PANEL UNIT WITH EAcTNG-REINEORCING AND TNSULATINGMEANS Filed May s, 1962 2 sheets-sheet 1 GEORGE F'. Bowman ATTY.

Aug- 18 .1964 G. F. BowDEN 3,144,701

CONCRETE WALL FORM PANEL UNIT WITH FACING-REINFORCING AND INSULATTNGMEANS Filed May 5, 1962 2 Sheets-Sheet 2 6o so/ 2z '-55 /9 Ta@ 30 Eg 3e32 74 54 519 lo WEA/TOR.

se 5o 59 32 22 GEoRGE F. BowDEN BY M4,

United States Patent() CGNCRETE WALL FORM PANEL UNllT Wl'irllFAClNG-REINFORCING AND INSULA'HNG MEANS George F. Bowden, Des Plaines,lll., assigner to Syntens Mfg. Company, Des Plaines, lll., a corporationof Delaware Filed May 3, 1962, Ser. No. 192,2@ 4 Claims. (Cl. 25-131)The present invention relates generally to a concrete wall form of thetype wherein two opposed and spaced apart series of rectangular panelunits in edge-to-edge relationship are adapted to have wet concretepoured into the space between them for wall-forming purposes and areconnected together by horizontal, transversely extending combined tieand spreader devices in order that they are prevented from separating ormoving apart under the thrust of the wet concrete. The panels which arecommonly employed in this type of concrete wall form consist of facingsof plywood against which the wet concrete is poured, and stiffening andstrengthening frames which are applied to and extend around the marginor edge portions of the facings. Such strengthening frames embodyhorizontal and vertical members or bars and also intermediate crossbarswhich extend either vertically or horizontally and are connected attheir ends to either the horizontal or the vertical marginal members orbars of the frames. The present invention has particular reference to aconcrete wall form of the particular type which is known in the art as aprefabricated wall form in that the individual panel units are assembledat the factory rather than in the field, and the panel-reinforcingframes, including the horizontal and Vertical marginal members, are inthe form of lengths of steel channel or angle stock which is rolled tospecial shape and perforated, notched, grooved or otherwise fashoined inorder properly to receive therein the edges of the plywood facings, aswell as to facilitate the use of suitable fastening devices or otherconcrete wall form hardware whereby the adjacent panel units may befastened together in edge-to-edge relationship.

Prefabricated concrete wall form panel units of the aforementioned typeare manufactured in standard sizes and, in order to reduce outwardbulging of the plywood facings by poured concrete against the facings,particularly in the larged units, it has been customary to reinforce theplywood facings with transverse members in the form of steel crossbarswhich extend horizontally across the rear or outer sides of the plywoodfacings and are welded at their ends to the vertical marginal members orbars of the panel-reinforcing frames. Such horizontally extendingcrossbars not only very materially increase the cost of manufacture ofthe panel units, but also are not altogether satisfactory in that theyreinforce the plywood facings only in localized regions with the resultthat noticeable bulging frequently takes place in the different facingregions which are not contacted by the crossbars, thus causing the sidesof the finished concrete wall to have a waffle-like appearance.

The present invention is designed to overcome the above noted limitationthat is attendant upon the construction and use of conventionalPrefabricated concrete wall form panel units and, toward this end, itcontemplates the provision in a panel unit of novel reinforcing meanswhereby the plywood facing is adequately and effectively reinforcedagainst outward bulging throughout its entire area.

Briefiy, the invention contemplates the provision in a concrete wallform panel unit of facing reinforcing means in the form of a sheet metalretaining pan which is generally arcuate in transverse cross section,has its 3,144,701 Patented Aug. 18, 1964 edge portions fixedly securedadjacent to the front edge regions of the opposed pairs of marginalmembers of the panel-reinforcing frame, and extends across the entirelength and width of the plywood facing. The pan, in combination with theplywood facing, defines a shallow, substantially semicylindrical pocketwithin which there is disposed a quantity of a cellular material whichis possessed of an appreciable degree of resistance to compressionalforces, but is nevertheless somewhat resilient while, at the same time,possessing high heat insulating properties. This material completelyfills the pocket and, since it is strong insofar as compressional forcesare concerned, any tendency for bulging of the plywood facing which itcompletely covers is assimilated by the metal of the pan A which isplaced under tension with the load being transferred either indirectlyor directly to the edge portions of the plywood facing. By such anarrangement, the use of crossbars or other reinforcing members iscompletely eliminated with the result that the improved panel unit as awhole is materially stronger and of less weight than a conventionalpanel unit.

Due to the fact that the cellular material within the pocket possesseshigh heat insulating properties, such material operates in the manner ofan outer jacket which insulates the poured concrete during the settingtime thereof so that, during cold weather operations, the need forapplying artificial heat to the panel unit is eliminated, as is the useof tarpaulins or other enclosures which sometimes are required to retainthe natural heat of hydration and thus maintain the concrete abovefreezing temperatures. Thus, due to the high heat insulatingcharacteristics of the cellular material, use of a panel unitconstructed in accordance with the principles of the present inventionresults in the elimination of such manual labor which, otherwise, wouldbe required for heat insulating preparation work.

Still further, according to the present invention, provision is made forthe application to the improved panel unit of a limited amount ofartificial heat, such heat being applied by convenient electrical means.The heat, thus applied, is intended for heat distribution purposes aswell as for replacement of heat losses, as Will become clear as thefollowing description ensues.

The provision of a reinforced and insulated panel unit of the characterbriefly outlined above being among the lprincipal objects of the presentinvention, numerous other objects and advantages will become readilyapparent as the nature of the invention is better understood.

In the accompanying two sheets of drawings forming a part of thisspecification, one illustrative embodiment of the invention has beenshown.

ln these drawings:

FIG. 1 is a fragmentary perspective view of one side 0f a concrete wallform showing a plurality of panel units constructed in accordance withthe principles of the present invention operatively installed therein inedge-to-edge relation;

FIG. 2 is a sectional view taken on the line 2-2 of FIG. l; and

FIG. 3 is a sectional view 'taken on the line 3-3 of FlG. 1.

Referring now to the drawings in detail, and in particular to FIG. 1, afragmentary portion of va concrete wall form of the pre-fabricatedmetal-reinforced panel unit type and embodying individual panel unitsconstructed in accordance with the present-invention has been designatedin its entirety by the reference numeral 10. The wally form selected forillustration is made up of a series of panel units, only three of whichappear in FIG. l, the three units being designated by the referencenumerals 12, 14 and 16. Adjacent or contiguous panel units are arrangedin edge-to-edge relationship, Except for the provision of the novelreinforcing and heat insulating means of the present invention, thevarious units 12, 14 and 16 are of more or less conventional shallowopen boxlike design and each panel unit is in the form of a rectangularplywood facing 18 and a marginal relnforcing frame applied to the outerface of the facing and consisting of vertical and horizontal marginalframe'bars 20 and 22, respectively. The bars Z extend in contiguity atthe juncture between the panel units 12 and 14, and at the juncturebetween the units 14 and 16. It will be understood that the series ofpanel units 12, 14 and 16 1s arranged in spaced opposition to a similarseries of panel units and is maintained in spaced relationship from suchsimilar series by means of conventional tie rod and spreader devices,fragments of which have been illustrated herien and designated in theirentirety by the reference numeral 24.

The vertical frame bars 20 are of shallow channel shape in cross sectionand each bar includes inside and outside, outwardly extending marginalribs and 32, respectively (see FIG. l and also FIG. 3), and a connectingweb portion 34. An integral laterally and inwardly extending seatingflange is spaced inwardly a slight distance from the inside edge of eachvertical frame bar and affords a right angle recess 36 in which theadjacent vertical edge portion of the plywood facing 1S seats with theinside face of the facing extending flush with the inside edge 19 of theassociated frame bar 20.

In erecting the concrete wall form 1t), the panel units 12, 14 and 16are brought into contiguity or edge-to-edge relation with adjacentvertical frame bars 2t) abutting each other so that the respective ribs36 and 32 are in edge-toedge abutting relationship while the webportions 34 remain slightly separated. At vertically spaced regionsalong the ribs 30 and 32, pairs of transversely registering notches 42are provided and these notches, when the vertical frame bars 20 are incontiguity, define therebetween horizontal channel voids which areadapted to receive therethrough the tie rods proper of the tie rod andspreader devices 24. A rectangular slot 46 is formed in the web portion34 of each vertical frame bar 20 at the horizontal level of each pair ofnotches 42 and is adapted to receive therethrough the usual T-bolt of abolt and wedge assembly 43 whereby the adjacent or abutting frame bars20 may be drawn tightly together.

The horizontal frame bars 22 are substantially identical in Itheirconstruction to the vertical frame bars 20 and, to avoid needlessrepetition of description, similar reference characters have beenapplied to the corresponding parts of both frame bars.

The arrangement of parts thus far described is purely conventional inits design and construction and no claim is made herein to any noveltyassociated with the same. Panel units of this type may vary widely intheir details of construction and it will be understood that eachconcrete wall form panel unit which is illustrated herein is purelyexemplary of one embodiment of a panel unit to which the reinforcing andinsulating means of the present invention is applicable. The novelty ofthe present invention resides in the reinforcing and heat insulatingmeans which is associated with each of the panel units 12, 14 and 16 andwill now be more fully described.

Referring now additionally to FIGS. 2 and 3, each panel unit has appliedthereto at the rear or outer side of the plywood facing 18 thereof apan-like retaining member 50 which, for convenience, will hereinafter bereferred to as a pan. This pan 50 is in the form of a section ofcomparatively thin flat sheet metal stock which is preferably sheetsteel of relatively light gauge and high tensile strength and has beenshaped so as to have an arcuate cross section as best seen in FIG. 3.The side edge regions of the pan are turned laterally outwardly toprovide attachment anges 52 which are welded coextensively as at 51 tothe seating flanges 35 of the vertical frame bars 20 on opposite sidesof the panel unit. These attachment flanges 52 are interposed betweenthe seating flanges 35 and the side edge regions of the plywood panel18. The upper and lower end regions of the pan are flattened andinwardly inclined as at 53 and the edge regions thereof are likewiseturned laterally to provide attachment anges 5S which are similar to theflanges 52 and similarly welded to the seating flanges 35 of thehorizontal frame bars 22.

The pan Si) is of such width that it bridges the distance between theopposed vertical marginal frame bars 20 and, in combination wtih theinside surface of the plywood facing 13, defines a generallysemicylindrical pocket 54 having a circumferential arcuate extent ofapproximately 36.

Vertically spaced horizontal struts 56, which may be in the form of atsteel bars, extend across the panel unit at the rear thereof and havetheir ends welded as at 58 to the rear margins of inside faces of thevertical frame bars 2t). While two such struts have been shown hereinfor illustrative purposes, it will be understood that a greater orlesser number of these struts may be employed. As previously stated, thepanel units are made up in standard sizes which vary in longitudinalextent but which are of uniform transverse width. Commercial units aregenerally two feet in width and they are made in selected standardlengths. Specifically, the units are made up in three, four, six andeight-foot lengths. The number of struts 56 is commensurate with thelength of any given unit. The various struts S6 extend in tangentialfashion across the crest portion of the associated arcuate pan and arewelded as at 59 thereto, the struts thus serving to reinforce themarginal frame bars 20.

Disposed within and completely filling the pocket 54 within the confinesof the pan 50 of each panel unit is a quantity or mass of a loadtransferring, heat-insulating material 6i?. While the mass may becomprised of various substances which offer the necessary -loadtransferring, water repellent, rot-resistant and heat-insulatingcharacteristics, the same is preferably formed of a cellular materialcontaining occluded air cells and commonly referred to as plastic foam.Chemically, the material is classified as a polyether urethane foam.Various grades of such plastic foam are manufactured and sold by theGlidden Paint Company of Cleveland, Ohio, under the trade name Glidfoem.It is contemplated that the particular grade of material (plastic foam)which is employed in each pocket 54 will offer an appreciable degree ofresistance to compressional forces, but will, nevertheless, be somewhatresilient. Such a material is widely sold at the present time for icebox insulation purposes.

As best seen in FIG. 3, the material 60 is coextensive with the entireinside face of each panel facing 18, as well as with the inside curvedsurface of the associated pan 50. The material is maintained undercompression within the pocket 54 and thus, when there is a tendency forthe panel facing 18 to bulge outwardly under the iniuence of the weightof the poured concrete, the load will be assimilated by the material 60and transferred, so to speak, first through the material directly to thepan S0 and then from the pan to the vertical and horizontal frame bars20 and 22, and also to the welded regions 62 of the struts 56, theseparts serving as reaction regions for direct assimilation of the thrustthat is exerted by inward bulging of the panel facing 18. By reason ofthe fact that the pan is arcuate in cross section it possesses acatenary effect and, together with the plastic foam material, serves toresist to a maximum outward bulging of the plywood facing 1S when thelatter is subjected to the outward force or thruust of wet concretethereagainst. By so reinforcing the facing 18 as to reduce to a minimumoutward bulging or deection by wet concrete thereagainst, the adjacentside of the wall which is formed upon hardening or setting of theconcrete will be for all intents and purposes flat. By reason of thecatenary effect of the pan due to the pan being arcuate in crosssection, the tension or outward bulging to which the pan is subjected bythe plastic foam material 60 in connection with placement of wetconcrete against the facing 18 is effectively opposed by correspondingcompression of the plywood facing.

It is to be noted at this point that, since the material 60 possessesgood heat-insulating properties, it may be relied upon to retain withinthe concrete form connes the heat of hydration which is generated withinthe poured concrete during hardening of the latter. Panels constructedin accordance with the principles of the present invention will,therefore, be found particularly useful in the field during exteremelycold weather when there is danger of freezing weather conditions. By theuse of the present insulated panel units, the straw, tarpaulin or otherconcrete enclosures which are commonly employed to prevent concretefreezing, and the attendant labor that is required in the erection ofthe same, may be completely eliminated.

Still referring to FIG. 3, it is to be noted that in the relatively thinregions of the pocket 54 where the side edges of the pan approach andcontact the attachment flanges 35 of the vertical frame bars 20, thethickness of the material 60 is considerably less than it is in themedial regions of the pocket. The protection to the adjacent regions ofthe poured concrete olered in the marginal regions of the panel unit isthus considerably less than is offered in the medial regions of theunit. Stated in other words, any heat of hydration which may begenerated by the concrete in these marginal regions of the panel issusceptible to being transferred through the metal of the pan 50directly into the flanges 35 and from thence into the adjacent metal ofthe frame bars 20. Accordingly, in order to counteract this tendency forheat escapement, an electrical resistance unit, such as has been shownat 70, may be embedded in the marginal portions material 60. Theresistance unit illustrated herein is in the form of a number of loops72 of insulated resistance wire which extend around and through thenarrow side and end regions of the pocket. The unit 70 has a terminalplugin connection 74 which may conveniently be positioned at anaccessible point on the pan 50. Energizing current for thet variouspanel units which are associated with any given concrete forminstallation may be of the 220-volt variety and supplied through acommon or manifold conduit (not shown) having suitable outletconnections for the various terminal connections 74 with provision beingmade for grounding the panel units through the conduit.

It will be understood that the resistance unit 70 is provided solely forthe purpose of supplying heat to compensate for heat losses byconduction in the marginal regions of the pan 50. The units 70 are notintended to supply external heat to the concrete mass undergoinghardening. From a commercial aspect, panel units which are intended foruse in above freezing temperatures need not be equipped with theabove-described heating means.

While one specific embodiment of a panel unit constructed in accordancewith the principles of the present invention has been shown anddescribed herein for illustrative purposes, it will be understood thatthe illustrated form does not indicate all the different forms of unitssuitable for the functions intended. The illustrated form is only one ofthose which have been developed for cornmercial application of theinvention. The invention, therefore, is not to be limited to theparticular form of panel unit which is specifically disclosed herein andit is intended to cover all modifications and alternative constructionsfalling within the spirit and scope of the invention as expressed in theappended claims.

This application is a continuation-in-part of United States patentapplication Serial No. 49,672, filed on August 15, 1960, entitledConcrete Wall Form Panel With Reinforcing and Insulating Means, and nowabandoned.

Having thus described the invention what I claim as new and desire tosecure by Letters Patent is:

1. As a new article of manufacture, a Prefabricated rectangular panelunit adapted to be arranged in an upstanding position and also inedge-to-edge relation with similar panel units and to form with suchsimilar units one side of a wall form into which wet concrete is to bepoured and then set for wall-forming purposes, said panel unitcomprising a normally flat rectangular plywood facing, a rectangularframe extending around and serving to reinforce the facing, having itsfront marginal portions connected to the marginal regions of the facing,having its intermediate and rear marginal portions projecting rearwardsof the rear surface of the facing and forming therewith a rectangularspace of appreciable thickness, a rectangular rearwardly bulged panformed of imperforate sheet material of comparatively high tensilestrength, disposed for the most part Within and shaped in outlinesubstantially conformably to said space, having its marginal portions,substantially throughout their entire length, connected ixedly in placeadjacent to the junctures of the front marginal portions of the frameand the marginal regions of the facing, and defining with said rearsurface of the facing a closed pocket, and a mass of material possessinglightness of weight, a cornparatively high degree of resistance tocompression and a slight amount of resiliency, disposed in and entirelyfilling the pocket, and arranged so that the inner surface thereof is incoextensive contact with substantially the entire area of the rearsurface of the facing and its rear surface is in coextensive contactwith substantially the entire area of the inside surface of the pan,said pan being for the most part uniformly arcuate in cross section fromend to end in order that it possesses a catenary effect, said mass beingof such character that when wet concrete is poured against the frontsurface of the facing and the facing thereby tends to bulge rearwards,it is placed under compression and any rearward pressure which it exertsagainst the pan, places the pan under tension and is, due to thecatenary effect of the pan, opposed by corresponding compression of thefacing with the result that the mass and pan effectively coact to resistto a maximum rearward bulging of the facing in connection with pouringof wet concrete against it.

2. A prefabricated rectangular panel unit as set forth in claim 1 andwherein the end regions of the pan are substantially flat and slopeforwards in the direction of the facing.

3. A Prefabricated rectangular panel unit as set forth in claim l andwherein the frame and pan are formed of steel, the marginal portions ofthe pan are bent laterally outward to form at coplanar attaching anges,and said flanges are in abutting relation with and welded directly toparts of the front marginal portions of the frame.

4. A prefabricated rectangular panel unit as set forth in claim 1 andwherein the material of which the mass is made is cellular plastic foam.

References Cited in the tile of this patent UNITED STATES PATENTS2,495,100 Henderson Jan. 17, 1950 2,640,249 Symons June 2, 19532,642,818 Talmey June 23, 1953 2,728,702 Simon et al Dec. 27, 19552,730,772 Jones Jan. 17, 1956 2,782,887 Zimmermann Feb. 26, 19572,907,070 Van Hartesveldt Oct. 6, 1959 OTHER REFERENCES EngineeringNews-Record article I, p. 2; Oct. 2, 1958. Engineering News-Recordarticle II, p. 55; May 12, 1960.

1. AS A NEW ARTICLE OF MANUFACTURE, A PREFABRICATED RECTANGULAR PANELUNIT ADAPTED TO BE ARRANGED IN AN UPSTANDING POSITION AND ALSO INEDGE-TO-EDGE RELATION WITH SIMILAR PANEL UNITS AND TO FORM WITH SUCHSIMILAR UNITS ONE SIDE OF A WALL FORM INTO WHICH WET CONCRETE IS TO BEPOURED AND THEN SET FOR WALL-FORMING PURPOSES, SAID PANEL UNITCOMPRISING A NORMALLY FLAT RECTANGULAR PLYWOOD FACING, A RECTANGULARFRAME EXTENDING AROUND AND SERVING TO REINFORCE THE FACING, HAVING ITSFRONT MARGINAL PORTIONS CONNECTED TO THE MARGINAL REGIONS OF THE FACING,HAVING ITS INTERMEDIATE AND REAR MARGINAL PORTIONS PROJECTING REARWARDSOF THE REAR SURFACE OF THE FACING AND FORMING THEREWITH A RECTANGULARSPACE OF APPRECIABLE THICKNESS, A RECTANGULAR REARWARDLY BULGED PANFORMED OF IMPERFORATE SHEET MATERIAL OF COMPARATIVELY HIGH TENSILESTRENGTH, DISPOSED FOR THE MOST PART WITHIN AND SHAPED IN OUTLINESUBSTANTIALLY CONFORMABLY TO SAID SPACE, HAVING ITS MARGINAL PORTIONS,SUBSTANTIALLY THROUGHOUT THEIR ENTIRE LENGTH, CONNECTED FIXEDLY IN PLACEADJACENT TO THE JUNCTURES OF THE FRONT MARGINAL PORTIONS OF THE FRAMEAND THE MARGINAL REGIONS OF THE FACING, AND DEFINING WITH SAID REARSURFACE OF THE FACING A CLOSED POCKET, AND A MASS OF MATERIAL POSSESSINGLIGHTNESS OF WEIGHT, A COMPARATIVELY HIGH DEGREE OF RESISTANCE TOCOMPRESSION AND A SLIGHT AMOUNT OF RESILIENCY, DISPOSED IN AND ENTIRELYFILLING THE POCKET, AND ARRANGED SO THAT THE INNER SURFACE THEREOF IS INCOEXTENSIVE CONTACT WITH SUBSTANTIALLY THE ENTIRE AREA OF THE REARSURFACE OF THE FACING AND ITS REAR SURFACE IS IN COEXTENSIVE CONTACTWITH SUBSTANTIALLY THE ENTIRE AREA OF THE INSIDE SURFACE OF THE PAN,SAID PAN BEING FOR THE MOST PART UNIFORMLY ARCUATE IN CROSS SECTION FROMEND TO END IN ORDER THAT IT POSSESES A CATENARY EFFECT, SAID MASS BEINGOF SUCH CHARACTER THAT WHEN WET CONCRETE IS POURED AGAINST THE FRONTSURFACE OF THE FACING AND THE FACING THEREBY TENDS TO BULGE REARWARDS,IT IS PLACED UNDER COMPRESSION AND ANY REARWARD PRESSURE WHICH IT EXERTSAGAINST THE PAN, PLACES THE PAN UNDER TENSION AND IS, DUE TO THECATENARY EFFECT OF THE PAN, OPPOSED BY CORRESPONDING COMPRESSION OF THEFACING WITH THE RESULT THAT THE MASS AND PAN EFFECTIVELY COACT TO RESISTTO A MAXIMUM REARWARD BULGING OF THE FACING IN CONNECTION WITH POURINGOF WET CONCRETE AGAINST IT.